The United States could finish 2026 with as many as 6,500 confirmed measles cases, infectious disease experts told Newsweek, as vaccine skepticism fuels outbreaks in under-vaccinated communities and threatens the country's measles-elimination status.
Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, predicted that the country would end the year with “roughly 6,000 to 6,500 confirmed cases."
“This is a return of the primitive,” Adalja told Newsweek, “a disease we eliminated a quarter-century ago, back by choice.”
The United States had recorded 4,080 confirmed cases this year as of October 8, already 78 percent more than the 2025 total of 2,289 cases. The highly contagious virus was declared eradicated in the U.S. in 2000 after the measles vaccine was developed decades earlier.
Measles-associated death counts this year differ between federal and state figures. The CDC has reported two deaths nationally, while Pennsylvania has confirmed five measles-associated deaths, including two infants, an 18-year-old and a 40-year-old woman. A sixth death reported by a county coroner remains under state review.
Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University Medical Center, agrees that the U.S. is on pace to reach 6,000 to 6,500 cases in 2026.
“That’s a reasonable order of magnitude of what we can expect,” Schaffner told Newsweek.
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Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, said he will watch whether the number of cases continues to rise.
“I think the bigger question is 'What happens in 2027?'” Hotez told Newsweek. “Historically, and in both 2025 and 2026, measles surges occur in late winter, early spring, so I think the worst is yet to come in February-March.”
“We have too many unvaccinated kids and adults,” he added. “They’re like warm water to a hurricane.”
Pennsylvania Outbreak Surpasses 1,200 Cases
Adalja identified Pennsylvania, Kentucky, Ohio, southwestern Wisconsin and Utah as areas he is watching closely.
Pennsylvania reported 1,222 confirmed cases across 42 counties as of October 14, including 86 new infections since October 9. The state also reported 225 hospitalizations and five confirmed measles-associated deaths. A sixth reported death in Franklin County is being investigated but has not yet been added to the state's count.
Adalja, who lives in Pennsylvania, said he expects “virtually every county in the state to be affected.”
Only four of Pennsylvania’s confirmed cases involved vaccinated people, representing less than 1 percent of its total. State officials have said two doses of the measles, mumps and rubella (MMR) vaccine are 97 percent effective at preventing measles.
“The virus hasn’t changed, and neither has the vaccine,” Adalja said. “Our willingness to use it has.”
A CDC map shows Pennsylvania had the most cases in the U.S. as of October 1, with 963. South Carolina followed with 670, then Utah with 535.
New York Governor Kathy Hochul issued an executive order earlier this month "declaring a State Disaster Emergency in response to the growing number of measles cases across rural areas of New York and neighboring states."
As of October 3, New York State has seen 108 confirmed measles cases, including seven in New York City, according to the governor's office.
Why Measles Is Continuing to Spread
Measles requires approximately 95 percent immunity to prevent sustained transmission, Adalja said, and the national kindergarten MMR coverage has fallen below that threshold.
Federal data released in August showed that national MMR coverage dropped to 92.4 percent and exemptions reached a record 4.2 percent.
Experts warned that national averages can obscure communities with considerably lower vaccination rates.
“We have now pockets of unvaccinated children all over the country,” Schaffner said. “Should the virus find its way into one of those communities, it would rapidly spread to those susceptible children.”
Adalja said that about 95 percent of this year's cases involved people who were unvaccinated or had unknown vaccination status.
“The large outbreaks this year are in tight-knit, under-vaccinated communities,” Adalja said. “In those settings, one introduction becomes hundreds of cases.”
Measles typically begins with a high fever, cough, runny nose and red, watery eyes, followed several days later by a distinctive rash that starts on the face and spreads down the body, according to the CDC. Severe complications can include pneumonia and encephalitis, or swelling of the brain, and the disease can be fatal.
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How Measles Returned to the United States
For Schaffner, the resurgence carries particular significance. As a young CDC Epidemic Intelligence Service officer, he helped investigate measles in Rhode Island and was the lead author of a 1968 New England Journal of Medicine paper documenting what happened after widespread immunization sharply curtailed transmission.
“Now here I am, in my gray-haired elder statesperson role, being aghast and deeply saddened that we're turning back the clock to the bad old days,” Schaffner told Newsweek. “Children are dying of measles. That number should be zero.”
Before a vaccine was available, more than 400,000 cases were reported annually, while the CDC estimates the true number of infections was between 3 million and 4 million each year.
The first measles vaccine was licensed in 1963, followed by an improved version in 1968 and the combined MMR vaccine in 1971.
The decline was dramatic. By 1981, just 3,032 cases were provisionally reported, representing a roughly 99 percent reduction in reported measles incidence since the vaccine's introduction.
But the disease was not gone. A major resurgence began late in the decade, driven largely by preschool children who had not been vaccinated on schedule. Cases reached 27,786 in 1990 and 9,643 in 1991.
The response came on two fronts. Following outbreaks among vaccinated school-age children, health authorities recommended a second MMR dose for all children in 1989. At the same time, federal, state and local officials intensified efforts to reach younger children who had missed vaccination altogether.
Will the US Lose Measles-Elimination Status?
The experts interviewed by Newsweek said the United States is at serious risk of losing its measles elimination status, which it has held since 2000.
“It is effectively gone, and the [Pan American Health Organization's] November review will make it formal,” Adalja said.
Adalja said losing the designation would mean measles had again become a domestically circulating disease rather than one principally associated with imported cases and limited subsequent transmission.
“That means more school exclusions, more exposure alerts at airports and hospitals, and more risk to infants too young to be vaccinated,” he said.
The Pan American Health Organization is scheduled to review the country’s elimination status in November after a decision was postponed earlier in the year. Elimination does not mean the country has no measles cases. Rather, the key question is whether the virus has reestablished continuous domestic transmission, which PAHO defines as circulation of the same genotype and lineage for at least 12 months.
Schaffner agrees that the designation will be lost.
“We’re going to lose the elimination status,” he said. “I think it will happen at the end of this year.”
Rebuilding Confidence in Vaccines
Confidence in the MMR vaccine was damaged in part by a 1998 paper that raised the possibility of an association between the vaccine and developmental disorders. The paper itself did not establish causation and was later retracted.
Subsequent scientific research has not supported a causal connection between MMR vaccination and autism. Yet vaccine skepticism has persisted and remains part of the national debate. Health and Human Services Secretary Robert F. Kennedy Jr. has continued to raise questions about aspects of MMR vaccine safety, while also acknowledging that the vaccine is highly effective at preventing measles.
Schaffner emphatically rejected the autism claim.
“Measles vaccine is not associated with autism in any form,” he told Newsweek. “It doesn't initiate autism. It doesn't exacerbate autism. That is a settled scientific question.”
But Schaffner said rebuilding confidence will require more than confronting skeptical parents with additional scientific evidence. People tend to hold on to deeply held beliefs even when confronted with contrary information, he said.
“Information alone rarely changes behavior,” Schaffner said. “Information goes to the brain. What changes behavior is how we feel.”
He said doctors and public health agencies need help from trusted people in communities, including religious leaders, business figures and other community leaders who can influence attitudes among families and peers.
“Local influencers, local thought leaders, the impressive people in the community can have a prominent role over time if they will be active,” Schaffner said.
He said vaccine attitudes have also become increasingly intertwined with politics, making public-health messaging more difficult.
“Measles will continue to occur in this country because there still is a lot of skepticism, hesitancy and indeed anti-vaccine sentiment,” Schaffner said. “It’s very hard to unring the bell.”
The CDC Response
CDC officials told Newsweek the agency is providing $100 million in additional funding to strengthen state, local and territorial responses to measles and other vaccine-preventable diseases through most of 2027.
The agency said federal teams had assisted Texas, South Carolina, Virginia, Kansas, New Mexico and Wisconsin with their outbreaks. Pennsylvania, which is experiencing the country's largest current outbreak, has formally requested CDC Epi-Aid assistance, according to the agency.
The CDC also said it is providing epidemiological, laboratory and technical assistance to health departments.
“Secretary Kennedy and CDC Director Dr. Erica Schwartz continue to make clear that the MMR vaccine is the most effective way to prevent measles,” the agency said.
Newsweek’s reporters and editors used Martyn, our AI assistant, to produce this story.
Contact Newsweek editors on this story: Sam Wilson.